Genocides have occurred since the earliest recorded history, from the Israelite destruction of numerous communities in Canaan, depicted in the Book of Joshua, to the Roman annihilation of Carthage and its population. But beginning with the Armenians, genocides have become more extensive, more systematic, and more thorough. They represent a lethal, depressing culmination of the large-scale violence that so marked the twentieth century. Genocides stand at the center of our contemporary cultural crisis. They challenge our hopes for peaceful, tolerant coexistence among diverse peoples; they raise the deepest fears that the modern world we inhabit is not a site of continual improvement in the human condition but the very cause of more intense, seemingly unstoppable violence against civilian populations. In this book I try to provide a historical account for the escalation of genocides in the twentieth century by examining in detail four cases: Nazi Germany, the Soviet Union under Lenin and Stalin, especially the ethnic and national purges initiated by Stalin, Cambodia under the Khmer Rouge, and the former Yugoslavia. Each of the cases has its particularities, but together they also display some notably common features, especially in relation to the historical origins and the practices of genocide.

The word "genocide" is a much contested and overused term. Sometimes it is uttered with thoughtless abandon, and I hope, through the study of these four cases, to bring clarity to a word and a history heavily laden with the emotions of memory and politics. The word was invented in the 1940s by the international jurist Raphael Lemkin, who struggled to find a way to define the novelty of Nazi atrocities against Jews. But Lemkin also knew that there were precedents, notably in the late Ottoman Empire's genocide of Armenians. He hit on the Greek word genos, meaning a people or nation, and the Latin suffix of -cide, for murder. The United Nations codified the meaning of the term by adopting on 9 December 1948 the Convention on the Prevention and Punishment of the Crime of Genocide, commonly known as the Genocide Convention. By one recent count, the Convention has been accepted by 142 countries.1

Nearly everyone who considers the definition finds it insufficient for one reason or another.2 It manages to be at one and the same time both too broad and too narrow. The Convention defines as genocide the intent to destroy "in whole or in part" a population defined by race, nationality, religion, or ethnicity. The Convention specifically does not include groups defined by their political orientation or class background. In the negotiations in the 1940s, the Soviet Union and its allies forced the exclusion of these categories for fear that its policies toward the peasantry and political opponents could be considered genocide. On the basis of the existing definition, for example, the regime in Indonesia could not be accused of genocide for the roughly 500,000 people it killed in 1965 because they were purportedly communists. The charge of genocide would be operative only if it could be shown that they were killed because of their Chinese ethnicity (as was true of so many of the victims). Similarly, if the Khmer Rouge were to come before an international tribunal, the indictment of genocide could be leveled only because of their treatment of Vietnamese, Muslims, and other minorities in Cambodia, but not for the vast repressions carried out against Khmer city dwellers and the educated elite. While the exclusion of populations defined by class and politics makes for too narrow a definition, the adoption of the qualifying term "in part" opens up a whole range of cases for consideration, including, for example, that of Native Americans.

For all of the difficulties surrounding the definition of genocide contained in the Convention, intentionality is clearly a critical criterion. For genocide to occur, there needs to be demonstrable intent to destroy "in whole or in part" particular population groups. This is a central point that distinguishes genocides from the civilian casualties that may occur in wartime, from pogroms, from massacres, from forced deportations--even if the number of victims is massive, and although any one of these actions may subsequently evolve into a genocide. By the criterion of intentionality, the atomic bombings of Hiroshima and Nagasaki were by no means genocides, however horrific the events, because the United States intended military victory over Imperial Japan, not the destruction of the Japanese people as such. One might also argue--though with much less certainty, I believe--that in its campaigns against Native Americans, the United States sought rather "typical," age-old territorial conquests achieved by warfare, not the physical annihilation of the Native American population.

Clearly, "intention" is not always easy to define. Since in most instances direct orders to commit genocide are rarely given, the case, both legal and historical, has to be built from the evidence of actions on the ground and often circumstantial links in the chain of command between those who occupy positions of power and those who carry out the actual killings. Despite some looseness in the wording that enables still looser readings, the Convention focuses on the physical destruction of defined population groups, not what is sometimes called cultural genocide or ethnocide (such as the forced assimilation of a group by preventing the use of its language). Nor does the Convention's definition encompass what we now call ethnic cleansing, the forced removal but not the killing of a population, although admittedly the line between genocide and ethnic cleansing can be quite indistinct. In fact, the initial General Assembly resolution of 1946 and the signed Convention of 1948 significantly narrowed Lemkin's original formulations, which had encompassed ethnocide and ethnic cleansing.3

Through its focus on intentionality, the fate of defined population groups, and physical annihilation, the Genocide Convention, despite its weaknesses, provides us with a fruitful working definition that can guide the study of past regimes and events. It is the definition I abide by in this book, though with perhaps a more restrictive interpretation than others might employ.4

In choosing the four cases for this study, I have been driven by concerns both substantive and personal in nature. To write about genocides in the twentieth century means grappling, of necessity, with the two very large and powerful dictatorial systems of twentieth-century Europe, Nazi Germany and the Stalinist Soviet Union. They happen to be, as well, the histories with which I am most familiar. But in writing a comparative study that moves closer to our contemporary world, I wanted also to trace the influences that these systems exercised, sometimes only indirectly, upon subsequent cases. The book is set up not only as the side-by-side examination of four parallel cases, but also as an exploration of the internal linkages among them. I do not argue that the Soviet Union and Nazi Germany learned from one another, although they were certainly highly attentive to one another's policies. They did, though, emerge out of a partly common historical background, notably World War I and the culture of violence that it spawned. And both systems had far-reaching reverberations that echoed well beyond their own life spans. Communism's influence extended out from the Soviet Union to the far reaches of Southeast Asia and the Balkans. As we shall see in the subsequent chapters, Soviet policies of the 1930s and 1940s had very direct bearing on the practices of the Khmer Rouge regime and of Yugoslavia even in its late stage of dissolution. Cambodia was of course spared Nazi influence, but Germany's occupation of the South Slav lands and its establishment of a puppet fascist state in Croatia in World War II played a significant role some fifty years later in the unraveling of Yugoslavia in the 1980s and 1990s. All the major actors in the Yugoslav crisis constantly referenced that history and mobilized its memory for their particular nationalist goals.

Another factor governed my choice of cases. A number of broad, general studies of genocides exist, and they have been important resources for me.5 Many more detailed studies of individual cases have been written, and I have learned a great deal from these as well. Yet historians (as I am) tend to be averse to the large-scale generalizations or even lawmaking to which many social scientists are prone. Historians favor the detailed study of a particular place and time; they seek to render the nuance that comes with knowledge of language and culture as well as empirical facts, and to be open to the indeterminacy of events. At the same time, that deep immersion in the history of a particular people makes it difficult to move beyond individual cases, beyond the national frame that structures not only modern politics but the training of modern historians as well. I have sought in this book to tread a middle ground, to write a comparative study that tries to be faithful to the historian's propensity for detail, nuance, and contingency, but that also goes beyond an individual case to examine how, in the modern world, political models, not only capital and commodities, move in a global space.6

Each of these cases continues to generate high-intensity politics and emotions, and my treatment of them comparatively will no doubt arouse the ire of some. The issue is perhaps most raw in relation to the Holocaust because it occupies such a prominent role in contemporary culture, and because prior efforts to deal with it comparatively have so often been mendacious. Prominent scholars like Ernst Nolte in Germany as well as neofascist activists have sought to diminish the crimes of Nazi Germany by comparing them to other cases or by arguing that the Third Reich "merely" copied practices pioneered in the Soviet Union or elsewhere.7 Needless to say, I completely reject that approach. But I also think that we should not allow our historical perspectives to be narrowed because comparisons have been done poorly or for notorious political purposes. The Holocaust was an atrocity of monumental proportions and the greatest tragedy in Jewish history. Like all historical events, it had its particular dimensions. The Nazis' industrial-style killing of Jews, rooted in Germany's highly developed bureaucratic and military culture, was and is unprecedented. But the Holocaust was not "unique" if by that term we mean an event that is incomparable and completely irreplicable. "Uniqueness" is a metaphysical or theological term. For historians, it can only have the mundane meaning that every event is specific to a time and place. Historians compare all the time, most often implicitly; indeed, the only way one could even sustain an argument of uniqueness is by comparison. If we insist on the incomparability of the Holocaust, we place it outside of history.8 Instead, I work in this book in an explicitly comparative manner. The obvious, underlying premise is that many states, not just Nazi Germany, have organized the systematic killing of populations defined along national or racial lines. We can learn at least as much by looking at some of these tragic events together, exploring their similarities and differences, their historical links to one another, as by studying each case individually.

Similarities and differences. Each case of genocide has its particularities, and among the four that I explore in detail, I distinguish two "genocidal regimes," Nazi Germany and Democratic Kampuchea. My intent here is in no way to relativize or diminish the tragedies suffered by various populations, but, again, to bring some analytical clarity to a topic that is so emotionally and politically charged. Historically all sorts of regimes have perpetrated genocides. From the fifteenth to the nineteenth centuries European settlers acting under the aegis of liberal states annihilated indigenous populations in Australia and North America. In the first decade of the twentieth century a semiliberal German state committed the genocide of the Herero in Southwest Africa. As I will argue in chapter 2, the Soviet deportations of Chechens and Crimean Tatars were carried out in circumstances designed to lead to substantial death rates, so these events can also be characterized as genocides under the terms of the UN Convention. But in none of these cases did genocide come to constitute the nearly exclusive, central motor of the systems. A panoply of policies and concerns--economic development, social welfare, military security--played equal or even more important roles. Nazi Germany and Democratic Kampuchea, in contrast, unleashed such a vortex of violence that at some point in their existence, the actual physical annihilation of defined population groups moved to the very core of state policies, and all the normal aspects of governance retreated to the shadows. While genocides have not been uncommon, regimes on the order of these two have, thankfully, been less typical.

In writing this study, I have violated one of the historian's cardinal rules: to work only on areas where he or she knows the language of the people and has access to the primary sources. I have ventured far from my core areas of knowledge but felt that the last two of my selections--Cambodia and the former Yugoslavia--were at least partly justified by my familiarity with the history of twentieth-century communism. Yet I did not feel free to roam just anywhere, and readers will note that I do not deal with another very large and virtually undisputed case of genocide, that of Rwanda. There I felt that my lack of knowledge of African histories and cultures was too great, that its story should be left to those with much more substantial expertise. Moreover, while Rwanda was certainly shaped by Western colonialism, it lies outside the realm of Nazi and Soviet influence, a key factor that influenced my decision to explore the histories of Yugoslavia and Cambodia.

Of all the cases with which I deal, the literature on Nazi Germany and the Holocaust is the most voluminous. Histories, sociological studies, memoirs, philosophical ruminations--the literature is so vast that it is now beyond the grasp of any individual. As mentioned, it is also the case in which resistance to comparative analysis has been the greatest. Part of my impulse in writing this book has been my frustration, as a historian of Germany, with the constrictions of the national frame in German history and in Holocaust studies. But in some ways, this book is also an attempt to apply the insights gleaned from decades of scholarship on Nazi Germany and the Holocaust to other cases around the globe. In particular, my emphasis in this book on the dual character of genocides, their organization by states but also their enactment with high levels of popular participation, comes out of the vibrant discussions in the German field.

The tragic events in Cambodia and Yugoslavia painfully exposed as chimeras two hopes that were already rather forlorn: that the revelation of Nazi atrocities would forever stand as an obstacle to the reprise of such crimes in other places and at other times, and that the collapse of communism would lead necessarily to more prosperous and liberated lives in postcommunist societies. Clearly, something deeper has been at work than Russian or German particularities or even the many crises of Europe in the first half of the twentieth century. Those deeper currents, in my view, have to do with the very categories of race and nation, those inventions that define the modern world so thoroughly that we can barely imagine our histories and our contemporary lives without them. While there is no unmediated, direct connection between these categories and genocide--many national and racial systems are "merely" discriminatory rather than murderous, and in each of the cases, many other historical factors have to be taken into account--they lie at the heart of the genocides of the twentieth century, which is why I begin this book with an intellectual history of race and nation.

In none of the cases discussed in this book was genocide predetermined or inevitable, not even in Nazi Germany. In the chapters that follow, I try to delineate the various elements that, together, led to the unfolding of genocides. The chapters on Nazi Germany, the Stalinist Soviet Union, Cambodia under the Khmer Rouge, and the former Yugoslavia are structured similarly. Each begins with a section titled "Power and Utopia," which is about the ideological orientation of the movements and regimes in question. In each case, the leaders were animated by powerful visions of the future and sought to create utopia in the here and now. The transformations they sought to implement were so substantial that I characterize all four regimes as revolutionary. The leaders viewed the state as the key agency in the creation of the future society and sought to build states that would exercise total control over society. Though profound differences existed in the contours of the future each intended to create, each imagined a society bereft of difference and marked by a homogeneous population of one sort or another. Hence all the regimes discussed in this book obsessively divided and classified the populations under their domains. They went to great lengths to define the legal criteria of identities and then to place individuals in their "proper" class, national, and racial slots, the subject of the second section of each chapter, "Categorizing the Population."

The genocides discussed in each of the chapters did not emerge suddenly, and they were not the only forms of killing that the regimes implemented. Generally the genocides emerged after particular groups had already been subject to discrimination and exclusion, and the population at large had been barraged with incessant propaganda about their nefarious characteristics. Political and class opponents had also been repressed and killed, and preparations had begun for more extensive population purges. The third section of each chapter details these critical historical processes that formed the essential background to genocide. But these harsh and brutal policies did not quite constitute genocides. Only at moments of extreme societal crisis--often self-generated--of immense internal upheaval and war, of great opportunities but also dread dangers, did the regimes initiate the most extreme form of population politics. The fourth section, "The Ultimate Purge," analyzes how each regime "tipped over" from pursuing discrimination and partial killings to perpetrating the more systematic and deadly policies of genocide.

These genocides were all the result of state policies. But genocides in the twentieth century became so extensive and systematic because the regimes engaged massive social projects that mobilized people for all sorts of activities, from the construction of dams to massive demonstrations to population purges.9 The literal reshaping of the population could not simply be decreed and could not happen overnight; it had to be created by the hard work of thousands and thousands of people, whether obtained through force, begrudging compliance, enthusiastic support, or the innumerable forms in between. In the penultimate section of each of the chapters, "Rituals of Population Purges," I use eyewitness accounts, trial testimonies, memoirs, interviews, and poems and novels to explore how large numbers of people became active participants in the brutalities of genocide.

These four cases of genocide that I explore in detail are not the only ones that have occurred in the twentieth century. A variety of authoritarian regimes, sometimes acting with the tacit or direct support of the great powers, have also perpetrated genocides. But the four I have chosen have been some of the most important ones. The commonalities I have found among them may not apply to every single case of genocide; other historical factors may come into play in other situations. But I would venture that the combination of factors I delineate--ideologies of race and nation, revolutionary regimes with vast utopian ambitions, moments of crisis generated by war and domestic upheaval--might, in some form, serve as guides to other cases and warning signs for the future.